An air spring assembly is mounted to a shock absorber to form a strut assembly. The strut assembly is mounted between a vehicle wheel and a vehicle body member. The strut assembly dampens road load inputs to a vehicle to improve passenger ride and comfort.
In a traditional configuration, the air spring assembly includes an air spring piston supported by the shock absorber, a flexible member, an external support sleeve, and an upper mount. The flexible member has a lower end portion and an upper end portion. The lower end portion is mounted to the air spring piston and the upper end portion is mounted to the upper mount to form a sealed internal volume. The upper mount is attached to a vehicle body member.
The external support sleeve surrounds the flexible member. Due to shock articulation, the external support sleeve has to follow movement of the flexible member and typically includes a flexible mount, which is undesirable.
Also, packaging the air spring assembly onto the shock absorber is challenging because the air spring assembly has to create a counteracting sideload in the shock absorber. Further, the air spring assembly requires a large internal volume to move the spring rate down as required for passenger car applications.
One solution has been to mount the air spring piston onto a shock absorber body, which is formed as an outer cylinder. The air spring assembly is then either angled off a vertical axis defined by the shock absorber body, or rolling lobes of the air spring (formed by the flexible member) are angled to generate the required sideloads. One disadvantage with this solution is that the air spring piston diameter is increased to fit around the shock absorber body at a certain angle. Thus, the air spring assembly requires increased packaging space as a result of the increased air spring piston diameter.
It would be beneficial to provide an air spring assembly that reduces the diameter of the air spring piston and eliminates a flexible mount for the external support sleeve, while still providing a desired spring rate. The air spring assembly should also be easily packaged in a smaller area, as well as overcoming other known deficiencies.